Summary

从小鼠眼中激光捕捉高纯大梁网的基因表达分析

Published: June 03, 2018
doi:

Summary

在这里, 我们描述了一个可重现的激光捕获显微切割 (LCM) 的协议, 用于分离小梁网 (TM) 的下游 RNA 分析。分析 tm 基因表达变化的能力有助于了解 tm 相关眼部疾病的基本分子机制。

Abstract

激光捕获显微切割 (LCM) 允许基因表达分析的单细胞和丰富的细胞群体在组织切片。LCM 是研究细胞分化的分子机制和各种疾病, 包括青光眼的发展和进展的重要工具。青光眼, 包括一个进步的光学神经病家族, 是世界上最常见的不可逆转的失明原因。结构变化和损伤内小梁网 (TM) 可能导致增加眼压 (眼压), 这是一个主要的危险因素, 发展青光眼。然而, 所涉及的精确分子机制仍然不太清楚。进行基因表达分析的能力对于进一步深入了解这些细胞的功能及其在眼压和青光眼的发展中的作用至关重要。为了实现这一目的, 需要一种可重现的方法, 从冷冻切片中分离出高度丰富的 TM, 并提出一种用于下游基因表达分析的方法, 如 qPCR 和 RNA 序列。本文提出的方法是从小鼠眼中分离出高度纯净的 TM, 用于下游数字 PCR 和微阵列分析。此外, 这种技术可以很容易地适应, 以隔离其他高度丰富的眼睛细胞和细胞室, 已经很难孤立的小鼠眼。LCM 和 RNA 分析的结合可以有助于更全面地了解青光眼的细胞事件。

Introduction

青光眼是一组以视神经病变和视网膜病变为特征的疾病, 最终导致不可逆转的失明1,2。据估计, 到 2020年, 全世界将有7000万人生活在某种形式的疾病中3,4,5,6,7。原发性开角型青光眼 (POAG) 是最普遍的青光眼类型, 其特点是水中幽默 (AH) 流出导致增加眼压 (眼压)8,9,10, 11,12,13,143,15,16,17,18。左不治疗, 长期升高的眼压导致视网膜和视神经头的渐进和不可逆转的损害导致桡盲症1,2,19。目前所有减缓青光眼进展的方法都集中在降低眼压, 或者通过降低睫状体的产率或增强其流出1,8,9,10,11,12,13,14. 小梁网 (TM) 在积极调节原发性 AH 流出通路中起着至关重要的作用, 其功能不当是高血压性青光眼1,2,19的诱因。然而, 与 TM 功能障碍相关的分子机制以及它如何调节 AH 引流尚未完全理解, 目前是青光眼研究的主要焦点1,2,19,20. 虽然一些基因组范围的联合研究 (GWAS) 已经将一些基因与青光眼联系起来, 而且对 TM 流出设施的抵抗力增加, 但导致疾病的确切分子机制还没有完全理解21,22,23,24,25

动物模型大大增强了我们目前对青光眼疾病进展的认识 (在3,15,16,26,27,28, 29,30,31,32,33)。研究 TM343536的一些开创性方法已经被广泛应用, 以促进我们目前对正常和病态组织的理解。尚未广泛探讨的一个领域是利用转基因小鼠模型研究 TM 失败的分子机制。转基因敲除和敲出小鼠研究 tm 相关基因, 如 Myocilin (Myoc)37,38Cyp1b139, 一直是研究 tm 分子机制的主要工具。功能。可以理解的是, 小鼠 TM 的微小尺寸代表了一个严重的障碍, 必须克服, 才能开始研究这种组织。老鼠模型是研究疾病遗传学和分子机制的有力工具, 而 LCM 技术的进步提供了必要的工具, 以授权研究最小和最微妙的组织, 包括 TM。

在本报告中, 提出了一种健壮的、可重现的方法, 用于从小鼠眼中提取高浓度 TM 的 LCM, 并与随后的 RNA 分离进行比较, 并对下游表达进行放大。类似的方法已经成功地用于小鼠分离其他类型的眼睛组织40,41,42,43,44, 本文所报告的方法可以应用到其他眼睛的离散组织研究 RNA, microRNA, DNA 和蛋白质。重要的是, 这种技术可以利用转基因小鼠更好地了解 TM 损伤的分子机制在青光眼和眼部疾病中的作用3,15,16,17 ,18,26,31,45,46。通过 LCM 分离小鼠眼 TM 的能力将是进一步深入了解几种眼部疾病分子机制的有用技术。

Protocol

国家环境健康科学研究所 (NIEHS) 动物护理和使用委员会 (ACUC) 根据 NIEHS 动物研究提案 IIDL 05-46 批准了这项研究的所有方法。 1. 激光显微切割的最佳组织采集 获得2到3月大的老鼠, 男性或女性 C57BL/6。弄死与 CO2的最小值为1分钟或直到呼吸停止。将动物从笼子中取出, 并通过颈椎脱位、斩首或开胸手术来保证死亡。 解剖前, 确保所有解剖工具清洁和消毒。<b…

Representative Results

从4种不同的小鼠中提取 TM 和睫状体的 RNA, 以便能够分析基因表达, 并比较从三只小鼠的全眼、巩膜、虹膜、视网膜、角膜和晶状体中的表达。在所有收集到的组织中分析了 tm 表达基因、 MYOC48和ACTA249 , 以确认在 tm 中, 分离的 tm 样品确实高度丰富。由于在 LCM 样品中的 cDNA 数量极低, 采用了数字 PCR 技术, 经证明可重现性更少…

Discussion

TM 在积极维持稳态眼压中起着至关重要的作用, 其功能障碍被广泛接受为高血压青光眼的主要病因1,2,19。GWAS 分析发现的几个基因中的单核苷酸多态性与青光眼风险的增加和对 TM 流出设施的阻力增加有关;然而, 导致这种疾病的精确分子机制尚未完全理解21,22,23</su…

Declarações

The authors have nothing to disclose.

Materials

ACTA2 ddPCR Primers (dMmuCPE5117282) BioRad 10031252 FAM
Agilent 2100 Bioanalyzer Agilent Technologies G2946-90004
Agilent RNA 6000 Pico kit Agilent Technologies 5067-1513
BioRad QX200 Droplet Digital PCR System BioRad
Small Paint Brush
Charged Glass Microscope Slide Thermo scientific 4951PLUS-001
Cresyl Violet Acetate Sigma Aldrich C5042
Curved Scissors
Eosin Y dye Thermo scientific 71204
Ethanol
Forceps Curved and Serrated tip (preferred tip size: 0.5 x 0.4 mm)
HemaCen American MasterTech STHEM30
High-Capacity cDNA Reverse Transcription Kit Applied Biosystems 4368814
Hsp90a ddPCR Primers(dMmuCPE5097465) BioRad 10031255 VEX
Leica CM1850 Cryostat Leica
Millex-GS filter unit EMD Millipore SLGS033SB 0.22 µm
MMI CellCut UV Cutting Model Molecular Machines & Industries LCM intrument
MMI CellTools Software Molecular Machines & Industries 50202 LCM software
Sample Tube for Laser Capture Microdisssection ASEE Products ST-LMD-M-500 Isolation Cap Tube/Manufactured by Microdissect GmBH in Germany and distrubted by ASEE Products
Sample Tube for Laser Capture Microdisssection (Alternative) Molecular Machines & Industries
modified Harris Hematoxylin Thermo scientific 7211 FAM
MYOC ddPCR Primers (dMmuCPE5095712) BioRad 10031252
PBS
Memebrane Slides, RNase Free ASEE Products FS-LMD-M-50r Polyethylene terephthalate (PET) membrane/Manufactured by Microdissect GmBH in Germany and distrubted by ASEE Products
Memebrane Slides, RNase Free (Alternative) Molecular Machines & Industries 50102
Rapid Fix Thermo scientific 6764212 H&E staining
RLT Buffer Qiagen 79216 lysis bufffer used for LCM samples
RNAseZap Sigma R2020 RNase decontamination solution
Protect RNA RNAse Inhibitor Sigma Aldrich R7397
RNeasy Micro Kit Qiagen 74004 RNA isolation kit
SMART-Seq v4 Ultra Low Input RNA Kit Takara Clontech 634888 low input RNA to cDNA kit for LCM samples
SuperMix (no dUTP) BioRad 1863023 digital PCR master mix
Tissue-Tek Cryomold (25mm x 20mm x5mm) Sakura 4557
Tissue-Tek O.C.T. Compound Sakura 4583
Stratalinker UV Crosslinker Stratagene 400075
Xylene Macron 8668

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Sutherland, C., Wang, Y., Brown, R. V., Foley, J., Mahler, B., Janardhan, K. S., Kovi, R. C., Jetten, A. M. Laser Capture Microdissection of Highly Pure Trabecular Meshwork from Mouse Eyes for Gene Expression Analysis. J. Vis. Exp. (136), e57576, doi:10.3791/57576 (2018).

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